Vitamin E is identified as any of a series of eight related compounds called tocopherols, with the alpha-tocopherol having the highest biological activity, and which is also associated with beta and gamma tocopherol. Tocopherol compounds are mainly present in plant materials, and generally are present in highest concentrations in plant materials such as wheat germ, corn, sunflower seed, rapeseed, soybean oils, alfalfa and lettuce. Vitamin E is a slightly viscous, pale yellow oil in the alpha-tocopherol form, and Vitamin E is believed to be required in certain human physiological processes, is subject to degradation on thermal exposure and in the presence of the atmosphere, and generally is employed as an anti-oxidant in vegetable oils and shortening, as well as pharmaceutical uses.
The tocopherol compounds constituting Vitamin E comprise a mixture of such tocopherol compounds, for example, derived from a natural product like soybean oil, the overhead fatty acid mixture from deoderization of the soybean oil, with the resulting mixture containing the alpha, beta, gamma and other tocopherols, and containing high molecular weight mixture of fatty acids and sterols, which must be separated in order to provide the Vitamin E compounds.
In view of the heat and oxygen sensitivity of the tocopherol compounds, it is customary to prepare Vitamin E from natural plant food mixtures employing molecular stills, which operate in the low micron range of pressure, which is determined from the mean free path of the molecules being processed, say, for example, from about one to fifty microns (millitorr). In some processing applications, a short path distillation procedure, such as thin film evaporation technology, may be employed, and may provide a crude mixture or fraction as desired. Similarly, whether molecular still evaporation or thin film evaporation technology is employed, it is nearly impossible to obtain high purity fractions or cuts in a single distillation pass; rather, fractions with increased purity can be obtained by multiple redistilling of the previous fraction. Thus, present separation and purification procedures provide for difficulty in operating or maintaining these high vacuum or molecular still and thin film evaporation systems, as well as high initial costs, and the difficulty of employing multiple distillations, particularly with heat- and oxygen-sensitive organic materials.
It is therefore desirable to provide for a new and improved system and method for the purification of Vitamin E, which overcomes many of the disadvantages, costs and inefficiencies associated with the prior art technology and to provide for a system and method for the purification of Vitamin E, and in particular an integral system with a single operation providing a high yield highly purified fraction of alpha-tocopherol.